Double-reciprocating split piston-rod for pumps



PATENT OEEICE.

JOHN A. BURNAP, OF ALBANY, NEW YORK.

DOUBLE-RECIPROCATING SPLIT PlSTON-ROD FOR PUMPS, 84C.

Specification forming part of Letters Paten-t No. 13,299, dated July 24, 1855.

To @ZZ whom t may concern:

Be it known that I, JOHN A. BURNAP, of the city and county of Albany, in the State of New York, have invented a new and useful Improvement in the Reciprocating-Rod- Gear Arrangement ot Double-Acting Pumps, which improvement is also applicable to other piston and valve devices connected with the workingot gases or uids, of which the following is a full, clear, andexact description, reference being had to the accompanying drawings, which form part of this specification, and in which- Figure l represents the top View or plan of a double-acting pump having my improvement applied to or forming part of it; Fig. 2, a partly-sectional elevation ofthe same viewed as indicated by the arrow X in Fig. l; and Fig. 3, a further partly-sectional elevation viewed as indicated by the arrow Z in Fig. l, Aat right angles to Fig. 2; Fig. 4, a transverse section of the split or double rod-gear de tached.

My invention has reference to that description of rod-gear arrangement in which two rods working through stut'ng-box contrivances are requisite for the necessary reciprocating actions, separately or in opposite directions, of two pistons or valves in a close cylinder or other chamber or chambers; and my improvement in such rod arrangement as operative gear for the pistons or valves consists in the use of a longitudinally split or divided cylindrical rod or two half or partially round rods arranged to Work through one and the same packing or stu'liing box separately or independently of the other each rod, and so that the flat or adjoining faces of the two rods act as guiding surfaces or bearings to each other, substantially as will hereinafter appear.

In the pump represented in the accompanying drawings the two pistons a and b, with their valves c and d, operate within a barrel or chamber d', and, in order to keep up the desired double action, are required to reciprocate simultaneously'in opposite directions, as is common to other double-piston pumps, from which the pump here represented does not differ in its general principle or action otherwise than in the arrangement of the supply-passage to the air-chamber relatively to the suction and discharge, which arrangement it is my intention to make the subject of a future application for Letters Patent.

The subject of the present application is exemplified by its attachment to or forming part of the pump.

In the case of two pistons a and l) operating as above described-1 hat is, reciprocating separately or in opposite directions within a close barrel or chamberwhether acting as plungers or buckets to suck and force alternately or as pistons to be propelled by the Water or other luid or gas, or whether such reciprocating contrivances be merely valves to admit and discharge or cut ott the operating gas or fluid, it is usual in all such wellknown applications or operations ot devices connected with the Working of gases or fluids to eit'ect the separate reciprocating movement of the two pistons or valves by two separate and entire rods in either one ot` the two following manners-that is, when these devices are desired to be operated both from or at the one side.

Round rods have been made to form a lateral connection with the pistons a and b by arms or direct attachment as may be, the rod of the one piston b being guided or passing through the other piston a, and the two rods arranged at such a distance apart as to admit of a rocking beam beinginterposed between them to work them, or they might be operated in any other manne-r. Such an arrangement is obviously bad. The widely lateral action of the rods on the pistons impairs the easy or even travel of the pistons and their rods. guiding travel one against the other, and, though necessarily required to be made stiff and weighty on account ot their independent disconnected action and the lateral strain upon them due to their positions, require extra or outside foreign guides to support them and keep them true in their proper course of travel, to enable them and the pistons to work freely or as nearly so as practicable under such an arrangement, and where the chamber through which the rods work is required to be a close one a separate stuiiing-box is necessary for either rod, to prevent leakage or escape of the fluid past the rods. Another ara-ngement is to operate the one (cylin- 'lhe rods have no bearing ordrical) rod within the other (tubular) one; but this, though avoiding the objectionable lateral strain adverted to, is au awkward arrangement for establishing the workin g of the rods with their outside gear by reason of their sameness of or central position, and on account of the inner rod being required to be extended. an inconvenient length to give it play outside the tubular rod throughout the entire stroke of the rods 5 also, a separate stuffing-box contrivance to prevent leakage is requisite for either rod, and the two rods, if fitting at first so as to act as guides for each other, soon cease to do so by wear, and cannot be adjusted to remedy such defect. All these objections are obviated by the arrangement I adopt, which is to take a single round rod and split or divide it longitudinally, or take two half or partially round or ready split rods s S and clamping them with their fiat faces together chuck and turn them, both rods at one operation. Previously to the turning-.of the two segmental or semicircular rods ss together their flat or straight faces should be ground on and true to each other to make a water or steam tight joint of their faces in contact.

To communicate to the two pistons or valves their separate reciprocating actions, or allow of Them with their rods moving independently of each other, and as exemplified in the double-acting pump represented in the accompanying drawings,the two halves or portions s and s of the split round or nearly round rod are separately connected, the one to the one piston a and the other to the other piston b, the latters rod passing through the first-named piston,.and are arranged so that the plane or straight faces of the two rods come in contact with or rub one against the other in the separate reciprocatingactions of the two rods. By this arrangement each rod acts as a guide and support tothe other, presenting a long and extensive bearing that materially serves to give a rm but free action to the working parts, prevent objectionable shake in the rods, and to strengthen them so that they may be made thinner or lighter than rods for giving like actions usually are. The rods will not only be guided in a true or straight vertical course, but be prevented from turning except bythe joint tendency of the two pistons simultaneously, which is very improbable, yet admitting of the pistons being turned when required by uncoupling the rods from their outside operative gear. In-

stead of being made plain or straight transversely on their faces in contact with each other, they may be grooved longitudinally, the ribs or projecting surfaces of ,either iitting into the grooves of the other, toimprove their action as guides to each other and the better to prevent lateral shake or vibration of the rods but such in a general way may be regarded as unnecessary, their plain, broad, and long straight surfaces in contact, as represented in the drawings, insuring a tolerably steady movement.

By it being practicable, for the reasons given, to make the reciprocating rods lighter than such rods for doing like work usually are power in operating them is economized, and their first cost reduced by the chucking and turning of the two rods at the one operation. One stufling or packing box m serves for both rods, andthe one operation of tightening down the stuffing-box secures the packing tight round either or both rods, and at the same time adjusts the adjoining faces of the two rods closer together, either by springing the rods toward each other or by moving them, as provided, by a loose attachment of them to the pistons or otherwise. This reciprocating double rod gear arrangement may be connected with any suitable outside voperative gear--as, for instance, for giving to the two pistons d and b their simultaneous reciprocating actions in opposite directions necessary to the double-action pump shown in the drawings-the rods may be operated by a cog-wheel n, having a reciprocating movement, and driving-racks i, one on either side, attached to the said rods s s', whose approximation to a central position prevents undue or injurious lateral strain on the pistons a and b.

Vhat I claim as new and useful in reciprocating rod-gear of valves or pistons operating essentially as and for the vpurposes herein set forth, and desire to secure by Letters Iatent, is

The double reciprocating split-rod gears s', when arranged and operating longitudinally side by side, as described, with the inner faces of the rods bearing against and acting as long moving guides and supports to each other, to strengthen them and prevent lateral shake or play, while their exterior is bound and tightened by the one packing-box, and the two rods or split portions s s', with their respective valves or pistons, are free to move separately or in opposite directions to each other, for the admission, discharge, or cutting ott of the gas or fluid, or for operation by the gas or iuid, as specified.

In testimony whereof I have hereunto subscribed my name.

JOHN A. BURNAP.

fitnessesz E. S, BEDELL, JAMES' H. MELICK. 

